1. Field of the Invention
The present invention relates to a process for producing an alcohol by a hydroformylation and a hydrogenation of an olefin.
2. Description of the Prior Arts:
it has been well-known that an alochol is produced by reacting an olefin with carbon monoxide and hydrogen by a hydroformylation and reducing the resulting aldehyde by a hydrogenation as an effective method of a production of an alochol, for example, a product of butanols from propylene (Yuki Gosei Kyokai Shi Vol. 35, No. 8, page 683 (1977)).
A carbonyl complex of the group VIII metal has been used as a catalyst in a hydroformylation of an olefin. When a rhodium catalyst such as a catalyst of a rhodium complex and excess of an organic tertiary phosphine is used, the catalyst has high stability and high catalytic activity whereby the hydroformylation can be carried out under mild conditions of a low temperature and a low pressure, and a yield of a straight chain aldehyde is high by using an .alpha.-olefin and they are remarkably advantageous in an industrial process as disclosed in J. Falbe, "Carbon Monoxide in Organic Synthesis" page 16 (1970).
The present invention relates to a process for producing an alochol by a hydrogenation of an aldehyde derived from an olefin by a hydroformylation.
In the conventional process for producing an alcohol from an olefin, an aldehyde produced by a hydroformylation of an olefin is separated from the reaction mixture obtained by the hydroformylation to eliminate the catalyst and by-products and then, it is used in the hydrogenation.
The reaction mixture contains the object product which may be easily cause a trouble such as a polymerization, and various kinds of by-products whose reactivities are unknown and the expensive hydroformylation catalyst such as rhodium component. Therefore, it is understood that disadvantageous results such as a decrease of an yield, an increase of a content of impurities and a loss of the catalyst are caused if the reaction mixture itself is used in the next step. Therefore, various processes for separating the object aldehyde from the catalyst such as a distillation or an extraction have been developed and proposed (for example, Japanese Unexamined Patent Publication No. 29412/1976).
Thus, these separations have certain disadvantages. For example, the distillation method has disadvantages that a thermal deterioration of the object aldehyde caused by low thermal stability; sometimes, excess of equipments caused by a high boiling point of the object aldehyde and an inactivation and a loss of the catalyst in the extraction method and they are not satisfactory. Thus, the hydroformylation of an olefin and a hydrogenation of the object aldehyde have been known, however, it has not been industrially worked, beside special exceptional cases, to produce an alcohol from an olefin by one continuous process.